Hello ! To do it well then forget about thewater volume and stick to the weight of the pot : Lift the pot when it's dry , then water and lift the pot when it's moist , you will have to water when the weight will be lighter ( dry soil but not too dry ) , you need to settle a wet / dry cycle in your soil. To avoid over feeding then you should also settle a water / nutrient / water / nutrients (reapeat untill the end) and if you see sign of over feeding then go with a water / water / fertilizer / water / water etc.. I hope it will help you ๐๐